Hi guys, I recently bought a used Trek Roscoe 22. After complete disassembly i noticed that the upper bearing cup was poorly made: the original piece of metal was welded at an angle, the hole for the steerer tube was cut off-center and the chamfer is not quite planar. The result is that the bearing cup is much thicker on the left side and that the metal underneath is much thicker on the right side. Interestingly, the bearing sits very nicely and without any play. Now I am a bike mechanic so rationally I do not think these defects produce any real threat because even 2 mm of metal should be more enough but I have two problems: first, it looks like shit and, more important, a part of me would not feel safe riding it. The frame is still under warranty and I have reached out to Trek hoping for a frame replacement since imo this should qualify as a manufacturing defect. My theory is that the headset was never serviced and the last owner did not noticed the problem. So what's your take? Would you ride it? Any Trek bike mechanic has had similare experience with aluminum frames? Any input will be appreciated, cheers.
by Conscious-Ear-6135
3 Comments
Are treks warranties transferrable?
Or do you know the original owner?
Hopefully you get a new frame.
I wouldn’t ride that, but you’re a mechaninc and would know more than me.
Is the headset bearing centered when it’s installed into the head tube?
Sooooo….. I’m not saying this to defend trek, I don’t care about the company, but I do have a hose in the race.
This is fine, it’s a matter of manufacturing. In a perfect world, the headtube would be completely round and parallel, but that’s not the case after welding, you WILL have distortion, every material will. They leave extra material and ream after welding, correcting the distortion and bringing the bearing seats back into parallel. Thus the bearing fitting well. It’s not that you’re wrong either, this isn’t great to look at, but it’s fine, and when assembled, will be un-noticed. If this kinda stuff bothers you, you shouldn’t look too close at anything, and definitely don’t ever put a frame on a surface plate. As a mechanic, that seems to be worried about these things, you should do a little reading on industry acceptance of tolerance. I think the last time I looked up frame alignment drawings from “insert big brand” in Taiwan, it was +-2.5mm, that’s 5mm off centerline from headtube to dropouts.
In short, just ride the bike, it’s fine.